Linux is great for gaming nowdays. I`ve got a little netbook with C-60 chip and Ubuntu 11.10. Ubuntu has a "software center" similar to Apple iTunes where you can find apps, games and stuff. Games and apps can be sorted by rating and installed by one click which is really cool and easy. Developing games for Ubuntu would be awesome. There`s free and commercial stuff in there.

http://www.ubuntu.com/ubuntu/features/ubuntu-software-centre